Liquid fuel feed control



Aug. 7,' 194s.

I1'. J. 'STEPHENS 2,381,372 LIQUID FUEL FEED CONTROL i 4 originalFiledAug. s, 194e` i 7? I i l q *76 70 l l 65 \l y HIGH FULL .LQ/izh-LOWFUELv l Y. Li/ C A v al n v j \V MNNOILLINEI y v v OVEN a7 L- Y.INVENTOR i, TmmnsJSi'ephens, W

Patented Aug. 7, 1945 .facilem- Theipresent#invention AL`relates;broadly-Lto the y l'lb iii-nglof-lliquidtuel;fsuchrforiexample.as f-uelfland has reference speciiically I to-the confthe result-that. an;'almost exact temperature can f be continuously maintained in thezoneoffheat -rrc onsum-ption- I `til/leans;i or-carrying theinventionintol eiTect; is

lustratively:5.exemplied :inthe. accompanying 4fdrawingfn whichtherlgure shows.J a control feed idevice:gappliedto-the baking chamberof an oven', whichchamber maylbe vconsideredas representae o f any zonewherein@heat'isr absorbed by a Aproduct lor, otherwise consumed orvrendered Referring tofthe drawing; Gland-163 denote ,two'uprightiflengths of gstandard .twoinch pipe which .farenunited by"means of a 4cross-fitting t4. The '.fupperxend offethezlowerfpipe 63`isrreduced by a bronzefinishing;` *65% havingan inside diameter ofinches. 4"Af-flen-gthnof light 1,1/2 inch diameter brass 'tube 16BIisrslidablyxdisposed through v*the bi-'shlirigwthin.thefpipesGZ and 63and is of sufcient length to extend below the bushing 65 and above thelevel of an atomizing nozzle 61 under allV conditions of service. Theupper pipe 62 is loosely closed at its top by a cap or other aplpropriate fitting having a concentric opening 69 at vits upper end. Ainch rod 10 passes slidably through the opening 68 in said cap and isconcentrically xed. at its lower end to the upper end of said brass tubeB6. The brass tube and rod assembly are slidably disposed relative tothe pipe assembly 62-63 in a manner which allows the rod and tube to beactuated by gravity. A radial arm 1I is attached to the Vpipe 62 bybeing clamped thereto near its upper end. At the outer end of said arman upwardly 'extending post 12 is xed, the upper end of which pivotallysupports one end of a movable lever 13. Intermediately of the postandthe pipe and on the f arm a pressure operated bellows 14 is located,vthe f lolledifeedvcfl sucnz fuel .un Aresponse to cheatwde- PATENTfoss-laca- LIQUID-FUEL FEEDJCONTROL n I I l U i V.'lj-hoiriarsQStephens, New York,

j oiginaiapplipation Auguste, `1940, serial No. l 350;927; Dvidedandthis application April24,

1... .-1943,serialfzNopisasso i bellows used being preferably of theknown ylphon typewhich -is* covered lby a protective "housing: 15having'a guiding tube V1f5'iitted cony''centrically'in"itstcp A"ro`d-11 isslidably iitted A5 inythe'tubewith its vlower 1 end resting on the"head-of theybellows and engages the said lever "1S-by means ofafslidable connection 18. The 'other-end jof the `lever 13 yisIpivotally andl slid- Y"aib'lyconnectedto^said rod 10 in such manner .10`fthat-upward or downward-movement of the leverv{jwillfrespec'ztive'ly,elevate and lower the tube. 'O pe'rfrings 119are-provided in the wallof the brassftbe (l'at-an elevation belowthelevel of @the'bu'rner nozzle'-when Atheitube is' in itsmaxifffngfuel'foil@from-iailsourcel of supply is connected 'ltoa-.pipe'l ywhich isconnectednto .one of the lateralfopenings ofsa'i'drcross-ttingll. The. op- `VApositella'teral opening of -lsaid cross isconnected i"ing-nozzle 61. ffAsthezpump istoperated, fuel :oil willflowinto the cross-fitting 64 and ll 'f the annular .space l'f'above I thelzbushing. '65. between the .pipe 62 and I thebrasstube' 66' untiliitsylevel reacheszthe open- Sings -1llin` the litube.y The oil thenzilowsthrough :,said .'openingsland Ydownwardly through; the brass vftube 62and: pipe :6311t'o a' return .pipe connection Iilfthrough'whichitlreturnsio .the source of fuel l 30. .iSupply from which; it-.was drawn 'by the pump.

'-In ith-is; manner faicontinuousisupply of fuel oil @in excessllof thatrequired bythe;operation is .fcirculate'd. .1-.rIhe1fuel' oil fin thelateral branch 1:18-2v`vhich suppliesuithe atomizer f61 will standat .35the'zsame ylevelzasin ltheseannular space in the lspipegZ. I Thus, byelevatingor': lowering the slidable tube 66, the Aoil supply level,below the atomizer in the pipe 82 is respectively elevated or lowered.Theatomizer nozzle 61 is of the 40 vaspirating or Venturi type and isoperated by a supply of steam or compressed air maintained at constantpressure, and delivered to the nozzle through a tube-84. Under constantconditions of aspiration the quantity of fuel projected from the nozzlewill vary on an inverse ratio to the distance through which the liquidis raised by the aspirating influence.

The said Sylphon bellows 15 mounted on the carrying 'arm 1| is providedwith a gasket to minute bleed opening 'in its base. The pressure tighttube 84 communicates between the interior of the bellows and the supplyof steam or compressed air which comprises the aspirating or atomizingagent for the fuel. An electrically .establish a pressure tight sealexcept for a operated valve 86, normally open, is placed in said lattertube. An electric switch normally closed is operative by a heatsensitive instrument thereby allowing pressure to be exhausted `fromtheinterior of the bellows 14 through said bleed opening 85. The lever arm13 is provided with a weight 89 which, together with the weight of therod and the tube 66 is sufficient to cause the tube 66 to descend aspressure is exhausted from the bellows 14, thus lowering the level ofthe liquid fuel in the supply pipe 82 to the atomizer, resulting indiminishing of fuel feed to the zone of combustion.

Inasmuch as the lifting power of the lever 13 is applied intermediatelyof its tWo ends and one end is pivotally fixed, it is obvious that therange of movement of the other end will be limited by the position ofthe lifting element 18. The housing 15 of the bellows 14 is slidablymounted onthe arm 1I in a manner such that it can be shifted along thearm 1I and fixed thereto in any position between a point near thefulcrum of the lever 13 and a point near its opposite end. The expansionof the bellows 14 is limited by its contactfwith the top of the housingv15, thus defining the maximumelevation of the rod 10. The descent ofthe rod 10 is limited to that position at which the lower end of theslidable connection 18 rests upon the upper end of the tube 16.lAccordingly, by adjusting` the position of the housing 15 together withits assembled parts 16, 11 and 18, the differential between the lowlevel and the high level of the opening 1S can be varied from a veryconsiderable differential to a very slight one to meet the requirementsof a wide variety of operations. For example, in an operation in whichheat consumption proceeds at a uniform rate a slight differential in thefuel levels resulting in a slight Variation between lowre and high fireis desirable; on the other hand, vin the case of an operation in whichheat consumption `is considerable for a short period and inconsiderableduring a succeeding period, a wider range between high re and low re isdesirable in order to cover both conditions economically. In all casesthe high fire should be such as to generate a quantity of heat slightlyin excess of the rate of heat consumption and the low re should be suchas to generate a quantity of heat slightly less than the rate of heatconsumption. The high fire will correspond to the high level and the lowfire to the low level of the fuel in the stand pipe 62.

It is to be noted that the present invention is useful only incombination with aspirating atomizers. The term aspirating atomizersdesignates that type of atomizing nozzle or device through Which gas,such for example as compressed air or steam under pressure, whenreleased through the nozzle, vis capable of elevating liquid from alevel beneath that of the nozzle -and projecting it, in finely dividedform,

suspended in the jet issuing from the nozzle. A synonym for aspiratingatomizer or nozzle is ,"Venturi-tube or Venturi nozzle or anycombination employing the Venturi principle.

I claim: l. In a heat generating and consuming apparatus, thecombinationfof a combustion chamber,

a stationary aspirating nozzle disposed to deliver atomizedliquid fuelinto said chamber, means for passing through said `nozzle an aspiratingagent maintained at uniform pressure, a rise pipe communicating betweensaid nozzle and a source of fuel supply, means for supplying fuel underpressure to said pipe, and an overflow `mechanism arranged forcooperation with said pipe to maintain the fuellevel inthe latter belowthat of the nozzle and including means for automatically varying thevertical distance between the level of said nozzle and the overflowlevel and, thus, the level of the fuel in said pipe in response to thevarying demand upon the combustion chamber for heat between apredetermined high level and a predetermined low level, both below thelevel of said nozzle.

2. In a heat -generating and consuming apparatus the combination of acombustion chamber, a stationary aspirating nozzle disposed to deliveratomized liquid fuel into said chamber,y means for passing through saidnozzle an aspirating agent maintained at uniform pressure, a rise pipedisposed between said nozzle and a source of fuel supply and incommunication therewith, means for supplying fuel under pressure to saidpipe and an overflow mechanism arranged for cooperation with said pipeto maintain the fuel level in the latter below that of the nozzle andincluding means for automatically varying the overflow level and thusvarying the level of the fuel in said pipe in response to the varyingdemand upon the combustion chamber for heat.

THOMAS J. STEPHENS.

